The Prophet works well with 650b wheels, I slapped the wheelset from my Beasely on my Cannondale for a few rides and liked it quite a bit. The Prophet is an awesome all 'rounder.
BTW - If anyone wants a large 2008 Prophet 3 frame, and a QR Fox Vanilla R let me know. I haven't listed mine yet but will soon. Likely selling the frame, fork, headset, front derailleur and seat post collar for ~ $600 (350 frame, 250 fork). I just rebuilt the fork in late October (new wiper seals and oil).